These lesson plans focus on the 2004 cruise to the Mariana
Arc called "Exploring the Submarine Ring of Fire."

Education Lesson Plans

The Ring of Fire is an arc of active volcanoes and earthquake
sites that partially encircles the Pacific Ocean Basin.The location of
the Ring of Fire coincides with the location of oceanic trenches and volcanic
island arcs that result from the motion of large pieces of the Earths
crust (tectonic plates). Tectonic plates consist of portions of the Earths
outer crust (the lithosphere) about 5 km thick, as well as the upper 60
- 75 km of the underlying mantle. The plates move on a hot flowing mantle
layer called the asthenosphere, which is several hundred kilometers thick.
Heat within the asthenosphere creates convection currents (similar to the
currents that can be seen if food coloring is added to a heated container
of water). These convection currents cause the tectonic plates to move
several centimeters per year relative to each other.

The junction of two tectonic plates is known as a plate boundary.
Where two plates slide horizontally past each other, the junction is known
as a transform plate boundary. Movement of the plates causes huge stresses
that break portions of the rock and produce earthquakes. Places where these
breaks occur are called faults. A well-known example of a transform plate
boundary is the San Andreas fault in California.

Where tectonic plates are moving apart, they form a divergent
plate boundary.At these boundaries, magma (molten rock) rises from deep
within the Earth and erupts to form new crust on the lithosphere. Most
divergent plate boundaries are underwater (Iceland is an exception), and
form submarine mountain ranges called oceanic spreading ridges. If two
tectonic plates collide more or less head-on, they produce a convergent
plate boundary. Usually, one of the converging plates moves beneath the
other in a process called subduction. Subduction produces deep trenches,
and earthquakes are common. As the sinking plate moves deeper into the
mantle, increasing pressure and heat release fluids from the rock causing
the overlying mantle to partially melt. The new magma rises and may erupt
violently to form volcanoes that often form arcs of islands along the convergent
boundary. These island arcs are always landward of the neighboring trenches.
This process can be visualized as a huge conveyor belt on which new crust
is formed at the oceanic spreading ridges and older crust is recycled to
the lower mantle at the convergent plate boundaries. The Ring of Fire marks
the location of a series of convergent plate boundaries in the western
Pacific Ocean.

Underwater volcanism produces hot springs in the middle of
cold, deep ocean waters. These springs (known as hydrothermal vents) were
first discovered in 1977 when scientists in the submersible Alvin visited
an oceanic spreading ridge near the Galapagos Islands, and made one of
the most exciting discoveries in 20th century biology. Here they found
warm springs surrounded by large numbers of animals that had never been
seen before. Since they were first discovered, sea-floor hot springs around
spreading ridges have been intensively studied. In contrast, the hydrothermal
systems around convergent plate boundaries are relatively unexplored.

The Mariana Arc is part of the Ring of Fire that lies to
the north of Guam in the western Pacific. Here, the fast-moving Pacific
Plate is subducted beneath the slower-moving Philippine Plate, creating
the Marianas Trench (which includes the Challenger Deep, the deepest known
area of the Earths oceans). The Marianas Islands are the result of
volcanoes caused by this subduction, which frequently causes earthquakes
as well. In 2003, the Ocean Exploration Ring of Fire Expedition surveyed
more than 50 volcanoes along the Mariana Arc, and discovered that ten of
these had active hydrothermal systems. The 2004 Submarine Ring of Fire
Expedition focussed specifically on hydrothermal systems of the Mariana
Arc volcanoes, and found that these systems are very different from those
found along mid-ocean ridges. The 2005 Submarine Ring of Fire Expedition
will explore hydrothermally active volcanoes in the Kermadec Arc, an area
where tectonic plates are converging more rapidly than any other subduction
zone in the world.

Each grade-level grouping includes activities that focus
on the exploration and research being conducted as part of this expedition.
In addition to being tied to the National Science Education Standards,
the hands-on, inquiry-based activities include focus questions, background
information for teachers, links to interesting Internet sites, and extensions.
Web logs that document the latest discoveries and complement the lesson
plans, complete with compelling images and video, will be regularly sent
back from sea. Teachers are encouraged to use the daily logs posted on
this site to supplement the lesson plans.

Read a description of each lesson plan and/or download them
to your computer. All of the lesson plans are available in pdf format,
and may be viewed and printed with the free Adobe
Acrobat Reader. To download a lesson plan, click on its title from
the listing below.

Students will be
able to describe the processes that produce the Submarine
Ring of Fire.

Students will be able to explain the factors that contribute
to explosive volcanic eruptions.

Students will be able to identify at least three benefits
that humans derive from volcanism.

Students will be able to describe the primary risks posed
by volcanic activity in the United States, and will be able to identify
the volcano within the continental U.S. that is considered most dangerous.

Students will be able to define and describe hydrothermal
circulation systems.

Students will be able to explain the overall sequence of
chemical reactions that occur in hydrothermal circulation systems.

Students will be able to compare and contrast black
smokers and white smokers.Given data on chemical enrichment
that occurs in hydrothermal circulation systems, students will be able
to make inferences about the relative significance of these systems to
ocean chemical balance compared to terrestrial runoff.

Students will be able to use fundamental relationships between
melting points, boiling points, solubility, temperature, and pressure to
develop plausible explanations for observed chemical phenomena in the vicinity
of subduction volcanoes.